Limiter for integral flexible circuit suspension assembly

ABSTRACT

A limiter used to limit the motion of a ring gimbal with attached slider relative to a load beam within a head suspension assembly of a disk drive. The ring gimbal includes a flexible substrate supporting at least one electrical lead and a limiter assembly joined to a portion of the flexible substrate. The ring gimbal also includes a tongue portion disposed within a substantially ring-like portion. The limiter is attached to a first surface of the tongue portion. The gimbal may further include a slider attached to a second surface of the tongue portion, wherein the second surface is opposite the first surface of the tongue portion.

This application claims the benefit of U.S. Provisional Application Ser.No. 60/360,161, filed Feb. 26, 2002, entitled “LIMITER FOR INTEGRALFLEXIBLE CIRCUIT SUSPENSION ASSEMBLY,” which application is incorporatedherein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to disk drives used for data storage andretrieval in computers. In particular, the invention is directed to alimiter for controlling the displacement of a portion of a ring gimbalwith attached slider relative to a load beam within a head suspensionassembly.

BACKGROUND OF THE INVENTION

Many computers utilize disk drives for data storage and retrieval, suchas magnetic recording hard disk drives that utilize a head assembly forreading and/or writing data on a rotatable magnetic disk. In suchsystems, the head assembly is typically attached to an actuator arm by ahead suspension assembly comprising a head suspension and anaerodynamically designed slider onto which a read/write head isprovided. When the head is positioned over a spinning disk during usage,the head position is at least partially controlled by balancing a liftforce that is caused by an air bearing generated by the spinning diskand acting upon the slider, and an opposite bias force of the headsuspension. In operation, the slider and head are designed to “fly” overthe spinning disk at precisely determined distances from the disksurface at speeds that can range from 3600 revolutions per minute toover 15,000 revolutions per minute.

Head suspensions generally include an elongated load beam with a gimbalflexure located at a distal end of the load beam, and a base plate orother mounting means at a proximal end of the load beam. The gimbalflexure includes spring or gimbal arms that support a platform or tongueto which the slider is mounted. During operation of such a disk drive,the gimbal arms permit the slider to pitch and roll about a load dimpleor load point of the load beam, thereby allowing the slider to followthe surface of the disk as it rotates, even if the disk surface iswarped, has an irregular topography, or the like. The gimbal flexure,including the gimbal arms and tongue, are thus designed to provide aflexible connection to allow the necessary pitch and roll of the sliderrelative to the rotating disk surface. In addition to the variations inthe disk surface, other operational and manufacturing considerationswithin the assembly itself can cause undesirable pitch and roll. Forexample, misalignment of components within the assembly can cause torqueto be placed on the slider, which can induce the type of pitch and rollthat can change the critical spacing between the slider and the disksurface.

Other head suspension assembly considerations are also important forproper alignment and performance of the various components. One othersuch consideration is the angular orientation of the tongue to which theslider is attached relative to the disk surface, which is also referredto as the “static attitude”. If the static attitude is not held toprecise tolerances, torque may be imparted to the slider, which can alsocreate undesirable pitch and roll of the slider relative to the disksurface.

In order to provide control of the critical spacing between the sliderand disk surface, the pitch and roll stiffnesses of the gimbal flexureshould be relatively low, which results in generally undesirable lowvertical stiffness. In cases where the gimbal flexure has a low verticalstiffness, the mass of an attached slider can be significant enough tocause the gimbal tongue to separate from the load beam by a distancethat causes permanent deformation or damage to the gimbal flexurestructure. This damage is particularly likely when shock loads areimparted to the head suspension during its manufacturing processesand/or operation within a disk drive. To protect the fragile gimbalflexure structure from such damage, the head suspension may be providedwith a limiter that, when engaged, can limit movement of the sliderrelative to the load beam, but still allows for low pitch and rollstiffnesses.

Various limiter features have been developed for use in head suspensionassemblies, particularly in the gimbal region of such assemblies. Forexample, in the traditional Watrous-style gimbals known in the art,various limiter features have been used which limit the motion of thegimbal tongue and prevent large linear and rotary deflections of thegimbal tongue and the attached slider, particularly during shock events.In other words, the features of the limiter may serve the purpose of“engaging” during shock events to limit certain types of movement. Ahead suspension assembly may be subjected to such shock during assembly,testing, and/or shipping, for example, which can cause components of theassembly to become undesirably deformed or displaced relative to eachother. Other shock events may occur when the suspension is part of apersonal computer disk drive that is dropped or otherwise subjected to asudden impact load that can cause the components of the suspension todisplace relative to each other and relative to a disk surface. In thesecases, a limiter can serve the purpose of preventing undesirabledisplacement of the gimbal tongue and slider components away from theload beam.

Previous versions of limiters involved forming a limiter prior towelding the various suspension components together. In these situations,a complex weaving motion was needed to properly position the tongue orgimbal component so that it could later be “caught” during shock events.This disadvantage was overcome with the use of components that allowedfor welding prior to forming the limiters, which facilitated theautomation of welding. Specifically, suspension components could bealigned or positioned relative to each other immediately prior towelding the components together.

Details regarding an integral flexible circuit suspension assembly and apolymeric ring gimbal which achieves very low pitch and roll stiffnesseswithout sacrificing high vertical and lateral stiffness can be found incommonly owned U.S. Pat. No. 6,515,832 to Girard, titled “GimbalStiffness Control for Head Suspension Assemblies”, the entire disclosureof which is incorporated herein by reference. The various features ofthis ring gimbal allow for setting nominal static angles whilemaintaining static angle positions throughout temperature and humiditychanges. However, at extremely high G forces, it is possible that thisgimbal may be damaged or distorted. Thus, it would be advantageous tooptionally add a limiter to a polymeric ring gimbal of this type forcertain applications or to add a limiter to other gimbal flexures thatcould utilize an additional protection feature. It would further beadvantageous that this limiter could be added without requiring anyweaving of components during assembly of the suspension and withouthaving to form the limiter after welding.

SUMMARY OF THE INVENTION

The present invention is directed to a limiter used to limit the motionof a ring gimbal with attached slider relative to a load beam within ahead suspension assembly of a disk drive. This limiter is particularlyadvantageous in that it can be joined directly to the tongue portion ofa ring gimbal without necessarily requiring any weaving of componentsduring assembly of the suspension. In one particular aspect of theinvention, a ring gimbal is provided which includes a flexible substratesupporting at least one electrical lead and a limiter assembly joined toa portion of the flexible substrate. The ring gimbal includes a tongueportion disposed within a substantially ring-like portion. The limitermay be attached to a first surface of the tongue portion. The gimbal mayfurther include a slider attached to a second surface of the tongueportion, wherein the second surface is opposite the first surface of thetongue portion.

The flexible substrate of the ring gimbal may be configured from anumber of different materials, including a polymeric material. Theflexible substrate may also include a plurality of material layers,where at least one of the layers can include copper or stainless steel.The limiter assembly may be configured so that a first limiter elementextends from a limiter support portion, which may include at least oneremovable section that is detachable from the limiter assembly.

The present invention also includes within its scope a head suspensionassembly including a load beam having a first surface opposite a secondsurface and a distal end, wherein the distal end comprises a windowopening, a ring gimbal, and at least one limiter assembly. Inparticular, the ring gimbal comprises a tongue portion disposed within asubstantially ring-like portion and is located at the distal end of theload beam and attached to the first surface of the load beam. The tongueportion comprises a first side that faces the first surface of the loadbeam and is at least partially visible through the window opening of theload beam. The limiter assembly or assemblies include a first limiterelement, wherein at least a portion of the limiter assembly is joinedwithin the window opening of the load beam to the first side of thetongue portion, and wherein the first limiter element is positioned tobe engageable with a portion of the second surface of the load beam tolimit displacement of the tongue portion relative to the load beam.

The present invention additionally includes a method of assembling ahead suspension assembly for use in a disk drive. The assembly stepsinclude providing a load beam having a first surface opposite a secondsurface and a distal end having a window opening and attaching a ringgimbal to at least a portion of the first surface of the load beam atthe distal end thereof. The ring gimbal comprises a tongue portiondisposed within a substantially ring-like portion, wherein the tongueportion comprises a first side that faces the first surface of the loadbeam and is at least partially visible through the window opening of theload beam. The assembly steps further include positioning a limiterassembly adjacent to the second surface of the load beam and the firstside of the tongue portion so that a first limiter element of thelimiter assembly is engageable with a portion of the second surface ofthe load beam for limiting displacement of the tongue portion relativeto the load beam, then joining the limiter assembly to at least aportion of the first side of the tongue portion that is visible throughthe window opening of the load beam. The limiter assembly may beprovided as a preformed unit, or the assembly steps may further includereconfiguring at least a portion of the limiter assembly in some wayafter the limiter assembly is joined to the tongue portion.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further explained with reference to theappended Figures, wherein like structure is referred to by like numeralsthroughout the several views, and wherein:

FIG. 1 is an exploded perspective view of a suspension assembly of thetype appropriate for use with a limiter of the present invention;

FIG. 2 is a bottom perspective view of a portion of a head suspensionassembly including a ring gimbal and limiter assembly;

FIG. 3 is a cross-sectional side view of a portion of the headsuspension assembly of FIG. 2, as viewed along lines 3—3 of FIG. 2;

FIG. 4 is a bottom perspective view of the limiter assembly of FIG. 2;and

FIG. 5 is a bottom perspective view of a head suspension assembly of thetype illustrated in FIG. 2, including another preferred embodiment of alimiter assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the Figures, wherein the components are labeled withlike numerals throughout the several Figures, and initially to FIG. 1,one preferred embodiment of a suspension assembly 10 is illustrated inan exploded perspective view. As shown, the suspension assembly 10includes a load beam 12 and a polyimide substrate 14 including aplurality of electrical traces 16 that are at least partially covered bya cover layer 18. Polyimide substrate 14 includes at its distal end aring gimbal 20, which is preferably designed to provide low pitch androll stiffnesses, high lateral stiffness, high vertical stiffness, andto have a low change in static attitude when subjected to temperatureand humidity variations. The polyimide substrate 14 also includes a neckportion 22 that provides a pathway for the electrical traces 16 back tothe drive electronics and an optional extending attachment tab 24 thatis appropriately sized and located for bonding or attaching the ringgimbal 20 to the load beam 12. In the preferred embodiment, thepolyimide substrate 14 will be adhered to the load beam 12 at first andsecond attachment areas 44 and 46, where the second attachment area 46can be adhered to the attachment tab 24, as described in further detailbelow.

Various portions of the polyimide substrate 14 could alternatively beattached to the load beam 12, particularly if the substrate 14 does notinclude an attachment tab; however, important aspects of the ring gimbalperformance may be affected. For example, if the ring gimbal 20 isbonded to the load beam 12 in the area in which the slider is mounted,the ring gimbal 20 may then become undesirably stiff in that area, whichcan affect the ability of the gimbal to pitch and roll as necessary. Itis further contemplated that when the ring gimbal 20 is bonded to theload beam 12 at the attachment areas 44, 46, it may also be bonded tothe load beam 12 at additional locations, if desired. In any case, anyadditional stiffness of the ring gimbal 20 at those locations where itis attached to the load beam 12 should preferably be considered in thedesign of the assembly to achieve the desired performance of the ringgimbal 20.

FIG. 2 illustrates the opposite side of a portion of the suspensionassembly 10 similar to the type shown in FIG. 1, including a load beam12, further illustrating the addition of one preferred embodiment of alimiter assembly 26 in accordance with the present invention.Additionally referring to FIG. 3, a cross-sectional view of the portionof the suspension assembly 10 taken along line 3—3 of FIG. 2 isillustrated. As shown in these Figures, load beam 12 generally includesa first portion 28, a ring portion 30 having an opening or window 32, aload point dimple 34, and a lift tab 36 that can be used to lift the endof the load beam 12 from the disk surface as necessary during thereading and writing of information on a disk. In this configuration,dimple 34 is recessed from the illustrated side so as to protrude fromthe other side thereof; however, the dimple may take any number ofconfigurations, such as a raised region, may have a different shape thanthat illustrated, may comprise a series of shaped surfaces, or the like.

The load point dimple 34 is preferably provided in a relatively stiffportion of the load beam 12 to provide a stable point about which thering gimbal 20 can pitch and roll. When the load beam 12 includes such aload point dimple, the ring gimbal 20 preferably includes acorresponding hole 47 that is appropriately sized and positioned toreceive the load point dimple when the ring gimbal 20 is attached to theload beam 12. The load beam 12 may alternatively be constructed withouta load point dimple, in which case it would not be necessary for thering gimbal to include a hole 47.

Ring gimbal 20 is preferably the distal portion of a larger polymericmaterial substrate, such as the polyimide substrate 14 that extends overat least part of the load beam 12. Ring gimbal 20 also preferablyincludes a tongue portion 38 to which a head slider can be mounted andthat is moveable relative to an outer ring portion 40. As shown, thetongue 38 is located within the outer ring portion 40, wherein thetongue 38 is optionally separated from the ring portion 40 by agenerally U-shaped channel 42 to allow the necessary range of motion ofthe tongue 38 relative to the outer ring portion 40 and the load beam12. As is visible in FIG. 1, the ring gimbal 20 preferably furtherincludes another channel or opening 48 separated from the channel 42 bya pair of torsion bars 49. Alternatively, the ring gimbal 20 may includemore or less than two channels or other types of openings to allow thetongue portion to be moveable relative to the rest of the ring gimbalstructure. It is preferable that the ring portion 40 and tongue 38 aremade from the same material, and is even more preferable that they aremade from a single sheet of material, where the channels 42 and 48 areremoved from a solid sheet of material to separate the tongue 38 fromthe outer ring portion 40. It is contemplated, however, that the tongue38 and surrounding ring portion 40 are made of different materials, suchas in assemblies where it would be advantageous for the two portions tohave different material properties (e.g., stiffness, weight, or otherproperties).

The tongue 38 is preferably biased or angled at least slightly relativeto the plane of the ring portion 40, which is preferably generally flator at a slight curvature. The tongue 38 is preferably flexible enough toallow it to flex at least slightly over the load dimple 34 when it reststhereon during operation. A portion of the tongue portion 38 thuspreferably abuts the raised dimple 34 so as to permit pitch and rollmovements of the tongue portion 38 relative to the load beam 12. Thering gimbal 20 may also include at least one deformation inhibitor (notshown) to reduce or prevent the additional pitch of the slider that canoccur if the polyamide substrate 14, and particularly the ring gimbal20, absorbs moisture from the air. These deformation inhibitors arepreferably trace extensions that extend from the electrical traces 16distally along part of the ring gimbal 20.

As shown best in FIG. 3, the polyimide substrate 14 in the area of thering gimbal 20 is preferably attached at certain locations to the loadbeam 12. Specifically, the polyimide substrate 14 is attached at firstand second attachment areas 44 and 46 to the load beam 12. Theseattachment areas 44, 46 are located on opposite sides of the load dimple34 and are spaced a sufficient distance therefrom to allow all necessarydegrees of motion of the ring gimbal 20 during operation of the diskdrive. The polyimide substrate may be a multi-layered structure thatincludes layers of the same or different materials, where the layer thatcontacts the load beam may include materials such as copper and/orstainless steel. If the polyimide substrate includes copper within itsconstruction, for example, the polyimide substrate could be adhered tothe load beam with any number of appropriate adhesives. If the polyimidesubstrate also includes another material such as steel, for anotherexample, the substrate may be attached to the load beam with laser weldsor other welding techniques at the attachment areas 44, 46. Theseattachment areas 44, 46 can be used in setting the static pitch angle,such as by varying the height at which those points are attached to theload beam. Although these attachment areas advantageously allow theflexible ring gimbal 20 certain preferred amounts of motion whileproviding the necessary constraints for controlling the position of thering gimbal relative to the load beam, it is understood that thepolyimide substrate 14 may instead be attached to the load beam 12 atany number of locations, which may or may not include the attachmentareas 44 and 46 described above.

The suspension assembly 10 can further include a slider 50 mounted toone face of the tongue portion 38. The slider 50 should be preciselypositioned on the tongue portion 38 at a predetermined location and canbe adhered or attached by any appropriate method. One exemplaryattachment method includes using an appropriate adhesive or epoxy thatmay be cured either with ultraviolet light or any other known curingmethod. In any case, it is important that the slider 50 is securelyattached to the tongue portion 38 so that it cannot move in anyunintended directions relative to the various components of thesuspension assembly. As discussed above, precisely controlling thespacing and positioning of the slider 50 relative to the spinning diskis critical for proper operation of the disk drive.

Referring additionally to FIG. 4, the limiter assembly 26 of FIG. 2 isshown. Limiter assembly 26 is preferably a spring steel layer that maybe part of a larger spring steel layer that extends along at least aportion of the suspension assembly 10 or part of a spring steel layerhaving other configurations used in an assembly of this type. Forexample, the spring steel layer may comprise an additional layercovering some or all of the load beam 12 for spring characteristics orthe like. As shown, limiter assembly 26 generally includes a ringportion 60, a limiter element 62, and an extension portion 64. The ringportion 60 and the limiter element 62 that extends from the interiorportion thereof are preferably formed into their desired shapes prior toany welding or joining operations with a suspension assembly. However,it is contemplated that all or some of the forming of the ring portion60 and limiter element 62 may occur after the limiter assembly 26 isattached to the suspension assembly. As shown, both the ring portion 60and limiter element 62 can include a plurality of bends or contours thatare provided as needed to permit attachment of the limiter assembly 26to the load beam 12 and the ring gimbal 20 while avoiding otherstructure. In this way, no complex weaving of the limiter assembly 26with the polyimide substrate 14 and/or the load beam 12 should berequired. However, minimal interweaving of the limiter assembly 26 withcomponents of a suspension assembly may be acceptable, depending on thestructure and relationship of the various components.

The limiter element 62 is preferably bent from the ring portion 60, suchas at a right angle or otherwise, in order to create an element capableof engaging the load beam structure at any point. The ring portion 60and limiter element 62 may include any number and variety of contours,bends, or other shaping to achieve a limiter assembly 26 that canprovide the desired functionality of limiting movement of the tongue 38and attached slider 50 relative to the load beam 12, as described infurther detail below.

Referring also to FIGS. 2 and 3, the limiter assembly 26 is illustratedin one preferred relationship with the load beam 12 and ring gimbal 20.In one preferred assembly operation, the various components of thesuspension assembly 10 are assembled and secured as described above,including attachment of the polyimide substrate 14 (having a ring gimbal20) to the load beam 12. The limiter assembly 26 is then placed in thedesired location relative to the load beam 12 and ring gimbal 20 so thatring portion 60 of the limiter assembly 26 extends generally into theregion of the ring gimbal 20. The extension portion 64 can beadvantageously utilized to properly position the ring portion 60 andlimiter element 62 relative to the ring gimbal 20 and load beam 12.Various methods and devices may be used to provide the precise alignmentof components that is necessary for these assemblies, where theextension portion 64 can provide a relatively large surface forpositioning that may be easier to align than the smaller components,such as the relatively small limiter element. Extension portion 64 oflimiter assembly 26 may be joined to the first portion 28 of load beam12 by any suitable method, such as welding or adhesives. The slider 50may be attached to the tongue portion 38 at any desired point in theassembly process sequence, but is preferably added to the assembly 10after the limiter assembly 26 is properly positioned and joined to thesuspension assembly 10.

In this embodiment, the joining of the limiter assembly 26 to load beam12 preferably occurs generally in the area designated by the letter ‘A’;however, the two components may be joined at one or more other suitablelocations, which areas may or may not include the area A. If thecomponents are attached at the area A, the amount of surface area thatis attached can vary widely. For one example, it may be desirable toprovide a more temporary type of attachment between the components sothat the extension portion 64 can be removed from the assembly after itis used for locating the limiter element 62. For another example, apermanent bonding method may be used so that the extension portion 64cannot be detached from the assembly.

As shown, part of the tongue portion 38 of ring gimbal 20 is visible andaccessible through window 32 of load beam 12. Any section or piece ofthe ring portion 60 of limiter assembly 26 that extends across window 32after proper placement of the assembly may be joined to ring gimbal 20at any point or points where these elements contact each other, which,in the preferred embodiment, includes at least one point of the tongueportion 38. In a preferred embodiment, the joining of ring portion 60 tothe tongue portion 38 of ring gimbal 20 is accomplished by adhering thetwo surfaces to each other; however, the surfaces may instead be joinedby another appropriate bonding or attachment method. As shown in FIG. 2,the relatively linear attachment portion 66 of ring portion 60immediately adjacent to the limiter element 62 is preferably joined tothe tongue portion 38. It is understood that this entire attachmentportion 66 may be joined to the tongue 38, but it is only necessary thata sufficient amount of this attachment portion 66 be bonded to thetongue 38 to adequately secure the limiter element 62 in its desiredposition to engage with the load beam 12.

The limiter element 62 is preferably configured and positioned so that aportion of element 62 can contact or engage the dimple 34 if the tongueportion 38 with the limiter element 62 attached thereto is moved. It isunderstood, however, that limiter element 62 could be formed to contactany other portion of load beam 12, such as any suitable point on itsring portion 30, for example. The limiter assembly 26 may furtherinclude additional limiter elements (not shown) that can contact variousportions of the load beam 12. If the assembly 26 includes multiplelimiter elements, the various limiter elements may be placed insymmetric locations about the ring portion 60 for purposes of balancingthe weight of the suspension assembly 10, or the assembly may bedesigned to accommodate limiter elements that are otherwise positionedabout the ring portion 60. Further, if multiple limiter elements areprovided, each limiter element may be similarly or differently sized,shaped, and/or configured, as desired, to prevent certain types andamounts of movement of the tongue portion 38. For example, a singlelimiter element may be a single extending portion with no bends, or alimiter element may include relatively complex bends and contours toproduce the desired shape for constraining a particular tongue portion.

Referring specifically to the illustrated embodiments of limiterassembly 26 that include a single limiter element, limiter element 62may be an integral portion of ring portion 60, where limiter element 16is simply bent or formed to the desired configuration. Alternatively,limiter element 62 may be a separate piece that is attached or joined toring portion 60, where the limiter element 62 and ring portion 60 maycomprise the same or different materials, and can be attached to eachother by any conventional attachment methods. It is further contemplatedthat all or part of the limiter assembly 26 may be made of materialsother than spring steel, such as polycarbonate or other polymericmaterials. The material or materials used for a particular limiterassembly 26 should be selected to have adequate stiffness to provide thedesired limiting function without breaking or deforming when engagedwith the load beam. The selected material should also be as light aspossible, however, because any added weight in this portion of thesuspension assembly can increase the chances of damage if a shock eventoccurs. Too much additional weight may also detrimentally affect theperformance of the suspension assembly and reduce the advantages gainedby using a polyimide substrate for the gimbal.

If the limiter assembly of the present invention is made primarily ofrelatively formable materials such as spring steel, various bending andforming operations will provide the desired configuration of the limitercomponents. Alternatively, some or all of the limiter assembly portionsmay be made of a material that is not particularly bendable or formablewithout breaking. If this type of material is used, the assembly must beinitially constructed in its desired final form, such as by injectionmolding, thereby eliminating the need for additional bending and formingoperations.

After assembly of the components as described above, the sections oflimiter assembly 26 that extend beyond the sides of the assembly willpreferably be removed. For example, the ring portion 60 may be severedby any shearing process, for example, generally along break lines suchas those shown as 70 a through 70 d. Such breaking of the ring portion60 creates a removable wing portion 72 that extends between the breaklines 70 a and 70 d, and a removable wing portion 74 that extendsbetween the break lines 70 b and 70 c. In this way, the section of ringportion 60 that includes the limiter element 62 and attachment portion66 would remain adhered to the ring gimbal 30 so that limiter element 62can perform its desired function.

To facilitate severing of the ring portion 60 in the desired locations,the break lines 70 a through 70 d may be scored or otherwise weakenedfor accurate breaking of the ring portion 60. Alternatively, the removalprocess may be automated or otherwise designed so that a tool or machinecan sever the ring portion 60 in exact, predetermined locations, withoutadditional markings of the ring portion. When choosing and designing thelocations for severing the ring portion 60 for removal of a portion orportions thereof, it is preferable that the break lines (such as lines70 a through 70 d in FIG. 2) are in locations that are accessible fromboth the top and bottom sides of the ring portion 60. This process ofsevering the ring portion 60 at break lines 70 a through 70 d andremoving the wing portions 72, 74 may take place at any desired point inthe assembly, shipping, and distribution process, as desired. Forexample, the wing portions 72, 74 can be removed immediately after theattachment section 66 is secured to the tongue portion 38 and beforeshipment of the suspension assembly 10 to a customer. Alternatively,removal of the wing portions 72, 74 may occur in a different processand/or at the same or a different location than where the limiterassembly 26 was attached to the suspension assembly 10. In this way, thevarious parts of the assembly, some of which are generally flexible, maybe kept more stable and aligned relative to each other throughoutvarious shipping and handling operations and the end user or assemblercan remove the wing portions 72, 74 when the assembly is less likely tobe subject to damage or deformation.

Accordingly, with the side sections of the ring portion 60 removed, alimiter element 62 is provided that extends from the attachment portion66 of the ring portion 60 that is attached to the tongue portion 38 onits oppositely facing side from the side thereof that is to be attachedto a head slider. By attaching the limiter element to this back side oftongue 38, the limiter element 62 can be positioned to engage any partof the load beam and to effectively limit movement of the tongue 38 andattached slider 50 away from the load beam 12, such as may occur under ashock load, and to limit the rotational movement of the ring gimbal 20.

It is also understood that in certain applications, the suspensionassembly with limiter can be designed so that no portions of the limiterassembly would need to be removed, such as the wing portions 72, 74described above. In other words, the entire ring portion 60 would becomea permanent part of the suspension assembly 10. However, because thering portion 60 would add weight to the area of the ring gimbal 20 andwould increase the overall size of the entire area of that end of theassembly 10, the corresponding disk drive and other electroniccomponents would need to be designed to accommodate such a suspensionassembly.

The ring portion 60 further comprises first and second leg portions 67,68 on opposite sides of attachment portion 66. Specifically, the firstleg portion 67 extends from the break line 70 d to the attachmentportion 66 and the second leg portion 68 extends from the opposite endof the attachment portion 66 to the break line 70 c. As shown, legportions 67, 68 are formed so that they overlay the ring portion 30 ofload beam 12, thus, they are bent or curved at least slightly away fromthe tongue portion 38, which is positioned below the ring portion 30 inthe illustration of FIG. 2. These leg portions 67, 68 can bespecifically designed to be separated by a certain distance from theload beam 12 under normal operating conditions, then to contact theportion of the load beam 12 over which they are positioned if deflectionof the tongue portion 38 occurs. Thus, these leg portions 67, 68 canprovide a second way of limiting the movement of the tongue portion 38relative to the load beam 12 when deflection occurs, in addition to thelimiter element 62 described above. Many variations and numbers of suchleg portions are contemplated, such as portions that are longer orshorter than that shown, or with different curvatures or bends thanillustrated. Alternatively, the ring portion 60 can be severed withinthe window 32 of the load beam 12 (i.e., closer to the limiter element62) such that no leg portions overlap a portion of the load beam 12.

FIG. 5 illustrates a portion of a suspension assembly 10 of the typeillustrated in FIG. 2, including another embodiment of a limiterassembly in accordance with the present invention. As shown, a limiterassembly 90 comprises an attachment portion 92 and a limiter element 94that extends therefrom. At least some part of attachment portion 92 isattached to the tongue portion 38 by any known attachment methods.Because this limiter assembly 90 does not include, for example, anextending portion 64 or ring portion 60, the assembly 90 itself must beprecisely located relative to the portion of the load beam 12, withoutadditional locating portions. This embodiment does not necessarilyrequire any additional severing steps, since the limiter assembly 90 ispreferably preformed to be the desired size, shape, and configurationbefore attachment to the tongue portion 38. However, any part of thelimiter assembly 90 could also be subjected to additional forming stepsafter the attachment portion 92 is attached to the tongue portion 38. Inany case, the limiter assembly 90 should be designed so that the limiterelement 94 can contact the load beam 12 at any desired point to limitmovement of the tongue portion 38 relative to the ring portion 30 ofload beam 12. The various configurations and materials that have beendescribed above relative to the limiter assembly 62 may similarly beapplicable to the limiter assembly 90.

The present invention has now been described with reference to severalembodiments thereof. The entire disclosure of any patent or patentapplication identified herein is hereby incorporated by reference. Theforegoing detailed description and examples have been given for clarityof understanding only. No unnecessary limitations are to be understoodtherefrom. It will be apparent to those skilled in the art that manychanges can be made in the embodiments described without departing fromthe scope of the invention. Thus, the scope of the present inventionshould not be limited to the structures described herein, but only bythe structures described by the language of the claims and theequivalents of those structures.

1. A head suspension assembly for use in a disk drive, the suspension assembly comprising: a load beam having a first surface opposite a second surface and a distal end, wherein the distal end comprises a window opening; a ring gimbal at the distal end of the load beam and attached to the first surface of the load beam, the ring gimbal comprising a tongue portion disposed within a substantially ring-like portion, wherein the tongue portion comprises a first side that faces the first surface of the load beam and is at least partially visible through the window opening of the load beam; and at least one limiter assembly comprising a first limiter element, wherein at least a portion of the limiter assembly is joined to the tongue portion of the ring gimbal within the window opening of the load beam at an interface between a surface of the first limiter element and a surface of the first side of the tongue portion, and wherein the first limiter element is positioned to be engageable with a portion of the second surface of the load beam to limit displacement of the tongue portion relative to the load beam, wherein the limiter assembly further comprises a limiter support portion from which the first limiter element extends and an extension portion extending from the limiter support portion, and wherein at least part of the extension portion is attached to the second surface of the load beam.
 2. The suspension assembly of claim 1, wherein the ring gimbal comprises a polymeric material.
 3. The suspension assembly of claim 1, wherein the limiter support portion comprises at least one removable section that is detachable from the limiter assembly.
 4. The suspension assembly of claim 1, wherein the limiter support portion includes a substantially ring-like portion from which the first limiter element extends.
 5. The suspension assembly of claim 1, wherein the at least one limiter assembly further comprises at least one additional limiter element extending from the limiter support portion, wherein the at least one additional limiter element is positioned to be engageable with a portion of the second surface of the load beam. 